B+W 65-072832 Neutral density camera filter 43mm ND 0.6-4X SC (102)

This B+W Neutral Density Filter reduces the light by two f-stops,
and it is the most popular ND filter in photographic work. It
offers many benefits, for instance f/4 instead of f/8 for selective
sharpness instead of a great depth of field, or 1/15 s instead of
1/60 s for a flowing instead of a “frozen” waterfall. It has
excellent color neutrality, costs less than the denser filters, and
is recommended as part of a basic outfit. The filter factor is 4x.